[U-Boot] [PATCH v6 1/1] usb: gadget: avoid variable name clipping in cb_getvar

* [U-Boot] [PATCH v6 1/1] usb: gadget: avoid variable name clipping in cb_getvar
@ 2017-04-03  9:28 Nicolas le bayon
  2017-04-03  9:50 ` Lukasz Majewski
  0 siblings, 1 reply; 5+ messages in thread
From: Nicolas le bayon @ 2017-04-03  9:28 UTC (permalink / raw)
  To: u-boot

From: Nicolas Le Bayon <nlebayon@gmail.com>

Instead of using a fixed-size array to store variable name, preferring a
dynamic allocation treats correctly all variable name lengths.
Variable names are growing through releases and features. By this way, name
clipping is prevented.

Signed-off-by: Nicolas Le Bayon <nlebayon@gmail.com>
Reviewed-by: Marek Vasut <marex@denx.de>
---

Changes in v2:
- instead of using a bigger fixed size, use malloc to fit with size needs

Changes in v3:
- v2 was an error (intermediate version), so propose a complete one

Changes in v4:
- be more explicit and detailed in label and description fields
- remove intermediate variable only used one time
- be more explicit in error message
- fix indent issue

Changes in v5:
- drop an unuseful error() call

Changes in v6:
- add Marek review approval

 drivers/usb/gadget/f_fastboot.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_
fastboot.c
index 2160b1c..7cd6d24 100644
--- a/drivers/usb/gadget/f_fastboot.c
+++ b/drivers/usb/gadget/f_fastboot.c
@@ -432,9 +432,15 @@ static void cb_getvar(struct usb_ep *ep, struct
usb_request *req)
                else
                        strcpy(response, "FAILValue not set");
        } else {
-               char envstr[32];
+               char *envstr;

-               snprintf(envstr, sizeof(envstr) - 1, "fastboot.%s", cmd);
+               envstr = malloc(strlen("fastboot.") + strlen(cmd) + 1);
+               if (!envstr) {
+                       fastboot_tx_write_str("FAILmalloc error");
+                       return;
+               }
+
+               sprintf(envstr, "fastboot.%s", cmd);
                s = getenv(envstr);
                if (s) {
                        strncat(response, s, chars_left);
@@ -442,6 +448,8 @@ static void cb_getvar(struct usb_ep *ep, struct
usb_request *req)
                        printf("WARNING: unknown variable: %s\n", cmd);
                        strcpy(response, "FAILVariable not implemented");
                }
+
+               free(envstr);
        }
        fastboot_tx_write_str(response);
 }
--
1.9.1

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